1.5: Unit Planning

Content Overview

Digestion and Nutrition: What foods do you eat and which ones form a balanced diet? What happens to these foods in your body?

This unit introduces students to the concept of nutrition, including selection of foods in their diet and what constitutes a balanced, healthy diet. Following the exploration of nutrition, students investigate the anatomy and physiology of the human digestive system-its structure and basic components, how it works to provide energy and the building blocks for cell functions, and some of its problems. Students are encouraged to use this knowledge daily to make good personal decisions and wise food choices. They conduct laboratory explorations to learn about nutrients, digestive enzymes, and the relationship between the structure and function of different parts of the digestive system.

Through exploration students learn that

Food is important because it provides the energy needed for body functions and the building blocks for body growth and the repair of tissues.

Each person requires a certain amount energy from food, measured in calories (Cal).

Digestion of food begins in the mouth where food is chewed and enzymes begin to break down carbohydrates. Digestion continues in the stomach where enzymes begin to break down protein.

Digestion of foods is completed in the small intestine through the action of enzymes from the pancreas and small intestine. The products of digestion are then absorbed through the intestinal wall.

Peristalsis, the rhythmic muscular contractions of the digestive tract, are important in helping digest and move food through the digestive tract.

Food choices are influenced by cultural and social forces and play an important role in maintaining good health.

How is the unit structured?

Section 1: Why Do We Eat?

Section 2: Food Is Fuel

PE Figure 2.2 Food pyramid

Section 3: Mouth to Stomach in One Swallow

Section 4: A Journey through the Intestine

PE Figure 4.7 Students' “capsule” surrounded by chyme particles.

How Is the Unit Structured?

Sections 1 and 2 introduce students to the study of nutrition, the six basic nutrients, and which foods contain each nutrient. Students complete activities to develop the idea of food as energy, measured in calories (Cal), which provides fuel and raw materials for daily activities.

Sections 3 and 4 focus on the processes of digestion. Through lab and text activities, students learn about the structure and function of the digestive tract. They investigate how foods are broken up into smaller particles by chewing and enzyme action. Through a simulation of peristalsis, students discover and experience how materials move through the digestive tract. They continue to explore the structure of the small intestine and calculate how much the villi increase surface area to facilitate absorption of digested foods.

Section 5 extends concepts of nutrition to explore some cultural and social influences and how we choose foods in response to these forces.

Section 6 addresses staying healthy and discusses other factors affecting digestive system function and good health. These factors include exercise, sleep, target heart-rate zone, and sources of stress.

Section 5: Food for life

PE Figure 5.3 Students use this map to discuss foods people grow and eat around the world.

Why Teach this Unit? Connections to the Real World

Adolescents appreciate the opportunity to make their own decisions. In order to make good decisions, they need information. This unit provides students with information about one of the primary body systems-a system that, through their choice of actions, affects their health, how they feel, and how they function daily.

How does the digestive system break down a bacon, lettuce, and tomato sandwich?

Digestion involves the physical and chemical breakdown of food into nutrients used by the body.

Physical breakdown of food includes chewing food in the mouth, churning food materials in the stomach, and peristalsis within the stomach and intestines.

Chemical breakdown of food occurs through enzyme action that breaks down large complex food molecules into small simple nutrients that are absorbed primarily in the intestines.

Mini Activity: Can You Tell the Types of Teeth?

Activity 3-1: Digestive Enzyme in Action

4 A Journey through the Intestine

How does your body get the nutrients it needs?

The pancreas and liver secrete important enzymes and substances necessary for the process of digestion.

The rhythmic contractions of peristalsis mix and move chyme through the intestines.

Nutrient absorption occurs primarily in the small intestine.

Osmosis and diffusion are the processes involved in absorption of digested food molecules (nutrients) from the small intestine into the bloodstream.

Mini Activity: Coil a Rope

Mini Activity: Shake It Up

Activity 4-1: A Journey through the Intestine (Peristalsis)

Mini Activity: What Passes Across a Membrane?

Activity 4-2: A Journey through the Intestine (Villi)

Mini Activity: Drawing the Actions of the Digestive System

Enrichment 4-1: Transport of Materials- Exploring Diffusion

Enrichment 4-2: Chemical Digestion Simulation

Enrichment 4-3: What Happens to the Digested Nutrients in the Small Intestine?

5 Food for Life

What factors affect what I eat?

Culture and family traditions and availability and cost of food affect what and how we eat.

Malnutrition and obesity are common food problems that can be corrected in many cases.

Anorexia nervosa and bulimia are two eating disorders that can cause severe health problems.

Mini Activity: Food Choice

Activity 5-1: Can You Become Obsessed with Food?

6 Staying Healthy

How can I keep my digestive system healthy?

Diet and nutrition play important roles in maintaining good health.

Staying healthy requires regular exercise and adequate rest.

Mini Activity: Your Target Heart-Rate Zone

Mini Activity: How Much Sleep Do You Need?

Mini Activity: Sources of Stress

Activity 6-1: You Are the Food Expert

Teacher's Guide Overview

The Digestion and Nutrition unit is built around a variety of student activities. Text material can be used to introduce, reinforce, and extend the concepts developed in the activities. The activities are the foundation of this unit, so the unit's success depends on students' involvement in the activities. Embedded activities are interrelated, since the concepts developed in one may be applied in another.

Section Planning

For each section, you'll find extensive advance planning for the student activities and the section topic. Key ideas, section objectives, background information, suggestions for introducing activities, and the materials needed for each activity are listed on the Section Planning page. Review this information ahead of time to ensure that materials for each activity are available when you need them.

Support for Embedded Activities

Embedded activities are those activities contained or “embedded” in the student edition. Procedures for each embedded activity are contained in the student edition. In the Teacher's Guide, you'll find activity planning information, activity assessment, and student reproducible pages for each embedded activity.

Enrichment Activities

Enrichment activities are activities found in the Teacher's Guide. These activities are designed to extend and enrich students' learning experiences. Complete Enrichment activities, including Teacher Activity Notes and the student procedures and reproducible pages, are located at the end of each appropriate section of the Teacher's Guide.

GroupWork Activities

Learning science is a process that is both individual and social. Students in science classrooms often need to interact with their peers to develop a knowledge of scientific concepts and ideas, just as researchers, engineers, mathematicians, and physicians who are working in teams do to answer questions and to solve problems. The GroupWork activities of the HumBio Curriculum for Middle Grades have been developed to foster a collaborative environment for groups of students. Students plan experiments, collect and review data, ask questions and offer solutions, use data to explain and justify their arguments, discuss ideas and negotiate conflicting interpretations, summarize and present findings, and explore the societal implications of the scientific enterprise. In short, GroupWork activities provide an environment in which students are “doing science” as a team.

For more information, refer to “Using GroupWork Activities” on TE page 98. The specific GroupWork activities for this unit can be found on TE pages 101-136.

Projects

The research and action projects in HumBio are varied and provide students with time to explore a particular topic in depth. With Projects, students have the opportunity to take a position based on knowledge gained through research, debate an issue, and devise a plan of action. In this way, students can apply what they are learning to larger issues in the world around them.

Projects for this unit include

Research Questions

A Nutritional Lunch

A Healthy Food Plan

Waste in the Fast-Food Industry

Examining Eating Disorders

Assessment Overview

Within each section of the unit there are suggestions for assessment that can be used individually or in combination to develop a complete assessment package. The list below describes the variety of assessment tools provided.

Apply Your Knowledge questions appear throughout each section. They can be used as homework assignments and as ways to initiate a class discussion. These questions are designed to assess

communication skills

depth of thought and preparation

problem-solving skills

ability to apply concepts to related or big ideas

how well students relate their new knowledge to different problems

What Do You Think?

These questions appear in each section. They provide students with opportunities to think and write about the concepts they are learning in a larger context. you can use these questions to assess

writing skills

problem-solving abilities

creativity and depth of thought

the ability to analyze and summarize

Journal writing prompts are suggested throughout the unit. These prompts provide opportunities for students to write critically and creatively about concepts and issues. The writing products can be used to assess

writing skills

depth of thought

and the ability to explain and expand on concepts

Review Questions

Review Questions are located at the end of each section. These questions can be used for written responses or as the basis for class discussion. These questions are designed to assess content knowledge and whether students can explain the concepts explored in the section.

Activity-Based Assessment

Inquiry-based student- centered activities are the foundation of the Human Biology program. The unit is rich with relevant and exciting activities that introduce, support, or reinforce concepts students are exploring. within the Teacher's Guide, you'll find extensive teacher information, including assessment strategies, for each type of activity:

Embedded Activities

Enrichment Activities

Mini Activities

GroupWork

Projects

You can use students' products to assess their progress. these products include models, simulations, observations and reports of laboratory investigations, role plays, written responses to quetions and written observations, student-designed explorations and procedures, poster presentations and classroom presentations.

PORTFOLIO ASSESSMENT

You may want to have your students develop a portfolio of the unit. A sample assessment portfolio of the unit might contain the following items.

Written responses to three What Do You Think? Questions

Written responses to one Apply Your Knowledge question from each section

An analysis of their two favorite activities and how those activities helped them learn an important concept

Reports from three investigations such as

Activity 1-1: Are You What You Eat?

Activity 3-1: Digestive Enzyme in Action

Enrichment 4-3: What Happens to the Digested Nutrients in the Small Intestine?

Two examples of constructing a model from

Activity 4-2: A Journey through the Intestine (Villi)

Enrichment 4-2: Chemical Digestion Simulation

Calculations from the following:

Activity 2-1: Calories: In a Nutshell

Activity 6-1: You Are the Food Expert

Getting Started

Keep Students Interested. Encourage students to read the text: It is the story line that ties all of the content together. Every effort has been made to make the text interesting to students and appropriate to their reading level. Text material can be used to introduce, reinforce, and extend the concepts addressed within the activities.

The success of the unit depends on the completion of at least the Embedded activities. And keep in mind that some activities are related since the data obtained in one may be used in another.

Plan Ahead. The unit is activity-based, and you can select the activities that will best meet your class' needs. The activities are listed in the Unit Activities chart on pages xiv and xv and in the Activity Index on page 150. Mini Activities are shorter and can be done with minimal teacher input; they are located in the margin of the student edition. The Embedded activities in the student text are investigations that require some planning and setup time; these are the essential activities within the unit. Other investigations called Enrichment activities are located at the end of each section in the Teacher's Guide. Enrichment activities expand student knowledge of the concepts explored in the given section.

A variety of projects were designed to extend the content of the unit. These include ongoing class projects, school projects, and/or community projects. Projects are located at the end of the Teacher's Guide, beginning on page 137.

Customize the Unit. Each section of this unit builds upon knowledge gained in the previous sections. Teaching timelines are provided on TE pages xxii-xxiii. The first timeline on TE page xxii demonstrates how to complete this unit within a three week schedule. The timeline on TE page xxiii demonstrates how to complete this unit within a five-week schedule. Both of these timelines highlight the essential activities. If your class has time to study the unit over a longer period of time, many additional activities are available.

Allow Time for Projects. Consider having students start projects at the beginning of the unit and then prepare those projects for presentation as a culminating event.

Use Current Events. Ask students to bring in newspaper and magazine articles that relate to what they are studying each week. Relating the unit content to current events helps students see that what they are doing in class is, in fact, relevant to their lives outside of school. Students can use current events to make group scrapbooks, bulletin boards, and posters or to develop class presentations.

Make a “question box” available. Have students write down questions they have about what they are investigating and put them in the box. At appropriate times select questions and read them to the class to generate discussion. These questions can also be used to initiate class research projects.

Use a Variety of Resources. We encourage you and your students to use a wide variety of sources for information. The activities provide rich opportunities for students to explore a variety of concepts. The more students incorporate information from resources outside the classroom, the richer their learning experiences will be. Use computer services for gathering student and teacher information, for networking with students in different schools and with community resources, and for contacting experts in the field under study. A list of resources can be found on page 148 of this Teacher's Guide.

Make Career Connections. Encourage students to investigate careers related to the content of the unit. Invite scientists, physicians, and technologists working in the field to come to your classroom to discuss career opportunities, their research, and specific topics of interest.

Plan for Field Trips. Field trips to local hospitals, industrial sites, or universities need, of course, to be arranged well in advance. Contact the public affairs offices of these institutions for assistance.

Address Health Concerns. Be aware of any special health problems your students may have. Some students may have health conditions that would make it uncomfortable for them to participate in certain activities, such as those that require exercise or that relate directly to their particular health problems. For students unable to participate fully in these activities you may wish to create an alternative assignment or have them use data from another group. If the class is appropriately prepared, the affected students may want to share information about their special circumstances with the class in order to increase empathy and knowledge of all students.

Connect with Other Disciplines. The interdisciplinary web provided is a guide for planning if your school uses an interdisciplinary team approach. The web classifies the unit's activities and projects by related discipline-language arts, math, social studies, physical education and health/nutrition, and visual performing arts, and science. For interdisciplinary planning, schedule meetings with your team early. You are encouraged to tap the talents and interests of your team members as well as of your unique school and community resources in developing other suitable activities for this unit.

Connect with the Home. Give special attention to the unit activities as a means of involving family and community members. Also, encourage your students to take selected Apply Your Knowledge questions and Mini Activities home for further exploration.

Teaching Timelines

You can use these timelines as a place to start in designing your own timelines, or you can use them as they are laid out. If you're planning your own timeline, consider the inclusion of the Embedded activities first. The “Embedded activities” are included in the student edition. The Enrichment activities, GroupWork activities, and Projects can then be included, depending on your time restrictions. The timelines are guides that can vary if some activities are done at home or in other classes in addition to science class.

Given your time constraints, it may not be possible to do all the activities shown on these timelines. If you need to remove activities, be careful not to remove any activities critical to the content of the unit. You may want to divide the activities among interdisciplinary members of your teaching team.

Page references in these charts refer to the student edition, except when Enrichments are suggested. The page references for Enrichments refer to this Teacher's Guide.

Option 1: Three Week Timeline

Monday

Tuesday

Wednesday

Thursday

Friday

Week 1

Introduce Section 1

Begin Activity 1-1: Are You What You Eat?

Continue Activity 1-1: Are You What You Eat?

Conclude Activity 1-1: Are You What You Eat?

Mini Activity: Write An Advertisement

Summarize and Review

Review Section 1

Introduce Section 2

Activity 2-1: Calories: In A Nutshell

Activity 2-2: Calories: How Much Energy Do You Use?

Assign Completion of 48-hour data table for Activity 2-2

Week 2

Complete Activity 2-2: Calories: How Much Energy Do You Use?

Explain the Food Pyramid

Summarize and Review Section 2

Introduce Section 3

Activity 3-1: Digestive Enzyme in Action

Summarize and Review Section 3

Introduce Section 4

Mini Activity: Coil a Rope

Activity 4-1: A Journey through the Intestine (Peristalsis)

Share Ads From Mini Activity: Write an Advertisement

Activity 4-2: A Journey through the Intestinal (Villi)

Mini Activity: What Passes Across a Membrane?

Week 3

Summarize and Review Section 4

Introduce Section 5

Mini Activity: Drawing the Actions of the Digestive System

Mini Activity: Food Choice

Activity 5-1: Can You Become Obsessed with Food?

Summarize and Review Section 5

Introduce Section 6

Mini Activity: Your Target HeartRate Zone

Activity 6-1: You Are the Food Expert

Mini Activity: How Much Sleep Do You Need?

Mini Activity: Sources of Stress

Summarize and Review Section 6

Unit Assessment

Option 2: Five Week Timeline

Monday

Tuesday

Wednesday

Thursday

Friday

Week 1

Introduce Section 1

Journal Writing Prompt: What are your favorite things to eat?

Activity 1-1: Are You What You Eat?

Mini Activity: Choices Are Everywhere

Continue Activity 1-1: Are You What You Eat?

Activity 1-2: What's In Your Food?, Part A

Continue Activity 1-1: Are You What You Eat?

Activity 1-2: What's In Your Food?, Part B

Finish and Analyze Activity 1-1: Are You What You Eat?

Assign Student Activity sheets-charts for

Activity 1-1: Are You What You Eat?

Summarize and Review Section 1

Introduce Section 2

Activity 2-1: Calories: In a Nutshell

Journal Writing

Activity 2-2: Calories: How Much Energy Do You Use?

Complete the 48-hour data sheet

Week 2

Complete Activity 2-2

Mini Activity: Reading Food Labels

Explain the Food Pyramid

Summarize and Review Section 2

Introduce Section 3

Activity 3-1: Digestive Enzyme in Action

Mini Activity: Can You Tell the Types of Teeth?

Follow the capsule through the system from mouth to stomach

Share Ads from Mini Activity: Design an Advertisement

Summarize and Review Section 3

Introduce Section 4

Week 3

Activity 4-1: Journey through the Intestine (Peristalsis)

Mini Activity: Coil a Rope

Complete Activity 4-1

Discuss the journey

Mini Activity: Shake it Up

Activity 4-2: A Journey through the Intestine (Villi)

Discuss the journey

Enrichment Activities 4-1: Transport of Materials-Exploring Diffusion, 4-2: Chemical Digestion Simulation, OR 4-3: What Happens to the Nutrients You Digest

Assign Mini Activity: What Passes Across a Membrane? (p. 39)

Enrichment Activities Continued

Week 4

Mini Activity: Drawing the Actions of the Digestive System

Summarize and Review Section 4

Introduce Section 5

Mini Activity: Food Choice

Journal Writing Prompt: Eating and the Five Senses

Mini Activity How Much Sleep Do You Need?

Activity 5-1: Can You Become Obsessed with Food?

Summarize and Review Section 5

Week 5

Introduce Section 6

Mini Activity: Your Target Heart-Rate Zone

Mini Activity: Sources of Stress

Work on Projects and/or Presentations

Activity 6-1: You Are the Food Expert

Review results of Mini Activity: How Much Sleep Do You Need?

Summarize and Review Section 6

Unit Assessment

Safety for Teachers

Always perform an experiment or demonstration on your own before allowing students to perform the activity. Look for possible hazards. Alert students to possible dangers. Safety instructions should be given each time an experiment is begun.

Wear glasses and not contact lenses. Make sure you and your students wear safety goggles in the lab when performing any experiments.

Do not tolerate horseplay or practical jokes of any kind.

Do not allow students to perform any unauthorized experiments.

Never use mouth suction in filling pipettes with chemical reagents.

Never “force” glass tubing into rubber stoppers.

Use equipment that is heat resistant.

Set good safety examples when conducting demonstrations and experiments.

Turn off all hot plates and open burners when they are not in use and when leaving the lab.

When students are working with open flames, remind them to tie back long hair and to be aware of loose clothing in order to avoid contact with flames.

Make sure you and your students know the location of and how to use fire extinguishers, eyewash fountains, safety showers, fire blankets, and first-aid kits.

Students and student aides should be fully aware of potential hazards and know how to deal with accidents. Establish and educate students on first-aid procedures.

Teach students the safety precautions regarding the use of electricity in everyday situations. Make sure students understand that the human body is a conductor of electricity. Never handle electrical equipment with wet hands or when standing in damp areas. Never overload electrical circuits. Use 3-prong service outlets.

Make sure that electrical equipment is properly grounded. A ground-fault circuit breaker is desirable for all laboratory AC circuits. A master switch to cut off electricity to all stations is desirable for all laboratory AC circuits.

Make sure you and your students are familiar with how to leave the lab safely in an emergency. Be sure you know a safe exit route in the event of a fire or an explosion.

For Student Safety

Safety in the Classroom

Wear safety goggles in the lab when performing any experiments. Tie back long hair and tuck in loose clothing while performing experiments, especially when working near or with an open flame.

Never eat or drink anything while working in the science classroom. Only lab manuals, notebooks, and writing instruments should be in the work area.

Do not use cracked, chipped, or deeply scratched glassware, and never handle broken glass with your bare hands.

Lubricate glass tubing and thermometers with water or glycerin before inserting them into a rubber stopper. Do not apply force when inserting or removing a stopper from glassware while using a twisting motion.

Allow hot glass to cool before touching it. Hot glass shows no visible signs of its temperature and can cause painful burns. Do not allow the open end of a heated test tube to be pointed toward another person.

Do not use reflected sunlight for illuminating microscopes. Reflected sunlight can damage your eyes.

Tell your teacher if you have any medical problems that may affect your safety in doing lab work. These problems may include allergies, asthma, sensitivity to certain chemicals, epilepsy, or any heart condition.

Report all accidents and problems to your teacher immediately.

HANDLING DISSECTING INSTRUMENTS and PRESERVED SPECIMENS

Preserved specimens showing signs of decay should not be used for lab observation or dissection. Alert your teacher to any problem with the specimen.

Dissecting instruments, such as scissors and scalpels, are sharp. Use a cutting motion directed away from yourself and your lab partner.

Be sure the specimen is pinned down firmly in a dissecting tray before starting a dissection.

In most cases very little force is necessary for making incisions. Excess force can damage delicate, preserved tissues.

Do not touch your eyes while handling preserved specimens. First wash your hands thoroughly with warm water and soap. Also wash your hands thoroughly with warm water and soap when you are finished with the dissection.